boogieman

i can't find anything on-line about coil geometry other than trial and error and think that there has to be a better way to accomplish this.

Go take a look at this site

http://www.instructables.com/id/Coilgun-Handgun/

lots of other links there, including THIS one : http://www.instructables.com/id/The-0-Coil-Gun/

REMEMBER : these are NOT toys and can kill and maim.

regards

To take a page out of Lemur's book ........

Ok, but what do you want to discuss. .......

Incidentally, that last photo ..... => Do YOU think that that is the real Governor of California??

I realize I may not have written questions to be answered, per se, but any commentary, opinions (criticism is welcome), insight, advice, accounts of personal experiences, anything at all would be very much appreciated.

I have left my previous major and am not sure at all where I am standing now, or what I should do. I am not looking for someone to tell me what I should do, but I feel like I lack information/knowledge that is needed to make my decisions.

Hi Ninlenn

Wrong forum, psychoanalysis was 3 doors back on the left. Career Guidance is two floors up, to the right of the elevators .

OK - Four stories here :

1. My dad knows a guy that studied (and practiced) pharmacy until the day HIS dad died, then gave it up and studied to be a veterinarian - his first love.

2. I (a civil engineer) know a civil engineer that has his Pharmaceutical Degree (first) hanging right next to his Engineering degree in his office - guess what carreer HIS dad forced him to pursue.

3. I studied with a guy that was a clerk on the railway for 9 years before he started studying Engineering => He was content with his station in life, it suited his abilities. It took him 12 years (compared to the normal 4 - he hit EVERY single subject THREE times to pass). Guess what?? His sister was a Doctor, his brother was a Lawyer, and his dad wanted to be able to say "My son - the Engineer.... etc." Hi dad has passed on and HE is now an unemployable Civil Engineer.

4. MY story => I "wanted" to be a Doctor (BIG push from my dad), decided to study pharmacy, did it part-time while conscripted for a 2-year stint in the army. Got severy wounded in combat and landed up in hospital for almost a year, got out and realized that I could NEVER spend 8-hours a day inside a building, went for Career Guidance and landed up in Civil Engineering providing services for the underprivileged => I am now as happy as a pig in Palestine and greet each dawn with a feeling of great anticipation.

Your story makes me wonder why you chose Nursing / Medical Sciences in the first place. Interlaced therein, there are enough references to lead me to believe that you are looking for a "Job", instead of looking for a "Career".

One's academic abilities (and IQ?) has got NOTHING to do with career-path decisions.

You are young enough to "Bread-Line", take the knock and find something that gives your life meaning. The alternative is waking up in 20 years time and hating the day ahead of you BEFORE you even get out of bed.

I think you are putting too much value on the "first generation" thing. Get yourself a good bottle of wine (or three?) and take an introspective look at your Needs, rather than your Wants (or your family/societies Wants, for that matter).

I am not looking for someone to tell me what I should do

Getting married will fix THAT quest very quickly - LOL

How did I suggest that electricity is like water flowing through a pipe? I just thought that pumping water into a tower would be a way to store energy as gravitational potential, that could drive turbines as it flowed back down at night.

Sorry, wasn't referring to you directly, was referring to a popular misconception, originally held by myself included.

All power can be stored by converting it into potential energy. This can be chemical potential as in batteries or mechanical potential in the form of compressed springs or gravitational potential in the form of mass elevated to some altitude.

I was specifically referring to storing AC in THAT form. Once again in layman terms, if I grab onto the terminals of a battery, I am going to land on my arlie and wonder what hit me. I wouldn't philosophize about "chemical potentials etc", I would consider myself as being shocked by electricity . In THIS context, AC cannot be stored.

Here I will concede that I have no idea how much energy would be lost in the conversion using a pump, water tower, and turbines on the down-pipe.

Neither would I - lol As a Civil Engineer, I could put a fair cost value to a couple of reservoirs, and divide it by the number of households in a typical residential area and come out with a reasonable accurate pay-back period of about 200 years.

I would like to know more about the efficiency of using chemical battery storage at the levels needed to save solar power everyday for nighttime use. The water tower idea seemed good to me because you could use the same water tower for many years whereas batteries seem to lose their ability to hold charge, which means they need replacing, which means they require factories, energy, and shipping to replace/recycle old batteries.

Because of various "mistakes of the past", our under-privileged communities developed in the absence of electricity, resulting in a massive market for battery-powered TV's. This in turn resulted in the development of a "Deep Cycle" car-sized battery. It holds charge better, can be drained to zero and be rapid charged without damage, and generally out-lives the conventional battery significantly. Regarding energy-efficiency, I can only imagine that it is more superior when compared to the energy losses anticipated when moving water to-and-fro, and the electrical/mechanical machinery involved.

I've read about it, too. I hope I didn't give the impression that it was my brainchild. I was just wondering if anyone knew how feasible it would be, how much power could be stored, the (in)efficiency of power loss in the process of pumping and driving a turbine as it flows back down, etc.

Sorry, it wasn't my intention to sound facetious. I slipped that in for the benefit of our other readers that may not be aware that the technology exists and is in fact already in use.

By "geyser," I assume you mean a gas water heater. If so, why remove these at all? Why not just teach people how to build their own solar water pre-heaters by connecting a bunch of CPVC water pipes and painting them black to use as a pre-heater? If their existing water-heater has a thermostat, it will automatically use less energy because the water was already hot when it entered the system. I think there may be some other problems with pressure build up in the CPVC pipes, but if you have clever people innovating, they should be able to work out the bugs and share the info with consumers.

South Africa is WAY not ready for gas. Our infrastructure never developed that way. In fact the only City that I am aware of ever trying it decommissioned their pipes about 20 years ago. I was referring to electric water heaters. Regarding CPVC, locally we have a thin-walled black pipe called LPDe. Your idea is already in use here, especially with regards to swimming pool heating. As I said previously, over here we have a lackadaisical attitude towards energy usage that will only get changed if/when Legislation forces it upon us.

My original response was not intended to criticize your OP, but rather to add additional comment on the topic for other readers to consider.

kind regards

How water tight are cars?

 

 

Not very...

That link ends BEFORE the toffee hits the Takkie.

The part 2 is the scary part.

The part about the doors staying jammed until the car settles on the bottom, sure isn't shown it Hollywood action movies - eh?

A boiled egg floats, but a fresh egg sinks. So you can go at sea and sink a fresh egg to make your experiment. Unless you want pressure by air and not by water.

 

It is supposed impossible to break an egg by pressing in the palm of a hand. Be careful doing the experiment.

Hal - michels suggestion has some merit.

Where I live (and fish), we get sea depths of 200meters (284 psi) within 12 kilometers of land. Simply by attaching the egg to your sinker and sending it down to pre-determined depths will be able to determine what pressure it will crush at. NO expensive container required!!

This will cancel out the "air leaking in" effect as discussed in other posts, and if WATER ingress is a problem, cling-wrap or varnish will solve that as well.

If you WANT the "air leaking in" scenario, putting the egg inside a plastic bottle may work. Gonna need a larger sinker though. The cap staying on might be your biggest problem.

I may even try this myself the next time I got out, will let you know - lol

Your level of detail is useful, as far as I'm concerned. I guess my question boils down to whether the power fed into the grid from a household solar panel gets conserved if it goes back through the transformer or whatever it is that intermediates power lines and household supply lines. I see what you mean that excess solar power could be sold to a direct neighbor without the energy having to go back onto the main grid, but I wonder if that's not its only possibility. It is interesting to picture entire grids consisting of solar-generating buildings where the excess power gets sent to a central storage-center, such as a water tower, but I wonder if it's even possible to get solar power from a grid to power a pump to pump water into the tower(s) during daylight hours.

my pennies worth of criticism :

1. The single biggest misconception that "laymen" , myself included, have is that we tend to think of electricity in the same terms as we see water flowing in a pipe. You need to toss that idea (the water concept).

2. AC power cannot be stored - someone please correct me if I am wrong.

3. The cost and energy wastage to build a water tower and pump water, boggles my mind. You would need TWO reservoirs (one high and one low), electric pumps, hydro-electric turbines, some serious invertors and probably a boat-load of batteries. You would NEVER recover your cost and the maintenance-issues will eat a hole in your peace of mind.

my pennies worth input :

1. Solar power (and any other home power for that matter), works on the basic principle of charging up Batteries (in DC), and THEN you draw your power from the batteries, convert it to AC to run the lawnmower, spa-bath etc. .

2. You are ALREADY storing surplus "power", why take it out your piggy-bank, send it up to your "water tower" and store it again, when all you need (at low cost) is to get extra batteries and release it directly into the net.

3. Your concept is good. So good in fact, that I seem to recall seeing something to the effect that there are municipalities out there that are in fact doing this very thing.

4. The biggest problem we have here in my country is convincing people to convert to home power. The cost to remove your old geyser and install solar is about 2 months of FULL salary. Of which the government rebates about half, but ONLY afterward. HOWEVER, if you build a NEW house, the cost difference only adds-on about 0.5% to your total cost, which will repay itself in less than one year, with the rebate - it would cost ZERO!!! ONE simple change to legislation to FORCE this onto new home builders will solve all my countries power problems.

TO : Jon13 and ANYBODY else who actually builds a prototype !!!!

PLEEEZE!! get someone with nerves of steel to video your maiden flight!!!! Myself and CaptainPanic REALLY want it for our video collections, and we don't want it spoiled when the cameraman tosses the camera and runs to call 911 - Hahahahahahaha!

Jon13 hasn't logged in since May 27, 2008... I don't think he will answer your question soon.

You think he tried to test-fly his prototype?

It is technologically possible to have nuclear powered aircraft. In fact, prototypes of the drive unit have already been manufactured and tested. in 1955!!!!!!! The power plant could either generate electricity to drive propellers/ turbines, OR it can be used to super-heat air and push through ram-jets.

Aircraft however, have an annoying habit to land in uncontrolled circumstances - euphemism for CRASH - LOL

Can you imagine the public outcry of a couple thousand atomic bombs taking off and landing daily around the world?

"The big problem with a nuclear-powered airplane is the disaster that would occur if it crashed. Because of this disaster-risk, the initial excitement around the idea has cooled. " quoted from :

http://blogs.howstuffworks.com/2010/04/05/is-it-possible-to-make-a-nuclear-powered-aircraft/

Nice historical link, notice which way the propellers are facing?

Hi there, I am a newbie here and "almost" a newbie to science forums in general. The "Boogieman" name was actually a misspelling I made a while ago, and by the time I realized it, it was too late so I've kept with it.

It should've been "Bogeyman" (like the guy who hides under beds and scares kids, and I spelt it like we say it over here) and not "The Boogieman" as in Neil Diamond - lol